AC Drain Line 101

The most common service call i get throughout the year is a CLOGGED DRAIN LINE ! It does not matter if your air conditioner is old or new this can happen to you. If overlooked this can cause irreversible damage to your AC system and possibly to your beautiful home.  Last year i had 309 services calls related to the drain line an average of almost 1 per day. This Problem is by far the easiest to fix as well as prevent.

Why Does The Drain Line Clog?

  • Dirty Filters
  • Algae Build Up
  • Lack Of Maintenance
  • Outdoor PVC Blockage

What You Will Need 

For cleaning (1 of the 2 will suffice)


Then for prevention (1 of the 2 will suffice)


Don’t use bleach. Bleach will damage copper, plastic and PVC. It will also caused the joint to leak by eating the glue away. People say use it when the AC is on in the summer because the water is washing it right out. However that’s not the case when it’s clogged or when there is little humidity the bleach can sit in there.Why use something that will eat the pipes and glue. Use Drain line cleaner or vinegar. Both work  just as good and does not damage the pipes.

Cleaning The Drain

Estimated Job Time: 10-15 min.

Tools And Equipment Needed: Shop Vac or Mighty Pump

Difficulty: Very Easy

Find the drain line. most commonly the drain is located near the condenser or outdoor unit.


Then attach  Mighty Pump or wet/dry vacuum and proceed to clear drain completely.











Estimated Job Time: 5 min.

Tools And Equipment Needed: Drain Cleaner or Vinegar

Difficulty: Very Easy 

Locate the air handler or indoor unit and remove the PVC cap from the drain line. Using a funnel or Pyrex, pour instructed amount NU Line or 1 cup of vinegar down the drain. Repeat this Process every time you change your air filter.

2 Replies to “AC Drain Line 101”

  1. Thanks for his information.

    I live in Greece and because it is so hot here, Air Conditioning in my home is a must!

    I have had to call in technical assistance on more than one occasion due to the drain line being blocked as well as other problem areas too.

    very often it has cost me excessive amounts of money to get it repaired (more than what i bought the unit for) and it has become quite frustrating.

    My air conditioning unit is never switched off. It is too hot. And even if I wanted to close if for a while to give it a rest, my wife would kill me!

    So, this looks like a great resource to come to for some DIY knowledge.

    Thanks, and I am hoping it will save me a few coins along the way!


    1. Thanks for checking back Mr. Towers. I had no idea you were checking out my site all the way from Greece nor did i know how hot it was there. I’m glad you found this tip so helpful and i guarantee it will save you some coin in the future. A drain line clog is almost inevitable without proper maintenance and prevention techniques.I hope this summer in Greece treats you well sir !

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